Speedo Cable Length With Ratio Adapter

[COPOZ/28]

My '69 Z28 was 'born' with a 4.88 axle ratio via COPO 9511CB, and therefore has the required 90 degree speedo ratio adapter, used only on 4.56 and 4.88 axle cars, in place on its original Muncie M22 trans.  My speedo cable acts like it might be starting to fail (intermittent speedometer needle vibrations).  This condition has been helped by pulling out and re-lubing the cable's inner drive core with distributor point cam lube but experience tells me this is a temporary fix.  I'd like to find the correct replacement speedo cable to purchase.  I'd also like to confirm if Z28s like mine (4.56 & 4.88 axles) with a speedo ratio adapter did or did not use any speedo cable support clips in the tunnel sheet metal.  My car has only one cable supporting clip hole in the tunnel area (not the two clip holes some have reported seeing on their car's tunnel) but there is no clip in that hole.

Would appreciate help with the following:

1. Was a speedo cable support clip(s) not used on 4.56 & 4.88 axle cars with the required 90 degree speedo ratio adapter?

2. Did 1969 Z28s originally equipped with the speedo ratio adapter use the same speedo cable length as Z28s with the 4.10 or 'taller' axles that didn't require the speedo ratio adapter?

3. If the answer to question 2 is Yes, is the 71" speedo cable offered by various parts suppliers the correct length for all 1969 cars with the Muncie 4-sp trans?  If the answer is No, would anyone know the correct length speedo cable for use with a speedo ratio adapter, and what source offers this length cable?

Thanks for helping.

[william]

Reference the 1969 Camaro Assembly Instruction Manual. Link is on this site under General Discussion.

Section G80 page A2
Section M20 page A9

[john302]

I  just purchased an original unrestored 69 L78 4 SPD 410 Rear with all original parts . The cable is shorter and of course the cable code is different .

[bcmiller]

I  just purchased an original unrestored 69 L78 4 SPD 410 Rear with all original parts . The cable is shorter and of course the cable code is different .

Are there any stripes visible on the driveshaft? If so, what is the build month of the car please?

[john302]

I can check

[john302]

Will post photos of the speedo adaptor and cable code /length of cable . Not often the assembly line speedo adaptor ,gear and cable are still with the car .

[GMAD_Van Nuys]

I had a similar problem with the speedometer needle bouncing on my 1979 Firebird.  I removed the cable, cleaned it and then lubricated it with lithium grease and it has worked without a problem.

There was a prior posting on speedometer reducers and I looked at the link to the Yenko website and could not find any part listing for 1969 speedometer cables, although there was information for reducers and speedometer gears: